Improvement in steam-generators



a sheetssheetm T. L. JONES. STEAM-GENERATORS.

Patented Aug. 21,1877.

FIG-S.

FIE-4.

WITNESSES. V M.

N,PETER& PHOTmLJTHnGRAPNER, WASHINGTON. DC.

UNITED STATES PATENT OFFICE.

THOMAS L. JONES, OF NATCHEZ, MISSISSIPPI, ASSIGNOR OF TWO-THIRDS HISRIGHT TO THOMAS P. L'EATHERS, OF NEW ORLEANS, LOUISIANA, AND JOHN P.KEISER, OF ST. LOUIS, MISSOURI.

IMPROVEMENT IN STEAM-GENERATORS.

Specification forming part of Letters Patent No. 194,440, dated August21, 1877; application filed February 7, 1877.

Natchez, Mississippi, have invented new and useful Improvements inSteam-Generators, of

which the following is a full, clear, and exact description, referencebeing had to the annexed drawings, making part of this specification, inwhich- Figure 1 is an elevation of the invention Fig. 2, a verticalsection, showing the parts within the generator partly in elevation;Fig. 3, a horizontal section on the line a; m of Fig. 2 and Fig. 4, ahorizontal section on the line 3 y of Fig. 2.

The same letters denote the same parts in the various figures.

The present invention relates mainly to a mode of generating steam bypassinga heated gaseous or vaporous current directly into the generator,and into contact with the water therein, and there retaining it untilits heat is communicated to the water, substantially as hereinafterdescribed.

The heated current may emanate from any suitable source, commonly anordinary fire, in which case the products of combustion, together withany air or other agent used in supplying the fire, are delivered intothe water-space of the generator. Such a heating agency is employed inthe present illustration of the invention.

Referring to the annexed drawings, A represents the shell of thegenerator or boiler. It may be of any desirable form and proportions. Asshown, it is of the upright cylindrical type.

B represents a fire-box or furnace-chamber. It is, preferably, locatedwithout the main generator, and at the side thereof, and it issurrounded, (saving at the top,) preferably, by a water-space, b, thatis connected at b b with the main water-space of the generator.

A suitable cover, b, is used to inclose the fire-chamber, when desired,and when it is needed a fastening, 12, maybe employed to hold the coverdown in place.

0 G O 0 represent the grate-bars of the furnace-chamber. They are,preferably, made hollow, opening at both ends into the waterspace b.

D represents the ash-pit. The chamber B is,-preferably, made very deep,being nearly or quite equal to thedepth of the water in the generator.There is an opening, I), in the side of the fire-chamber, just above thegrate, for the insertion of a poker, and, if preferred, similar openingscan be inserted at various levels above the grate. There is also anopening, d, in the ash-pit for the removal of ashes. It may be at theside, or in the bottom, of the pit, as preferred. All of these openingsmay be closed by doors or removable plugs.

Tubes E E lead from the fire-chamber into the main generator, asfollows: The tube E from the upper part of the fire-box, and from above,or at the level of, the top of the fire, and the tube E from the ash-pitI), or at or below the bottom of the fire, and both of them through theconnections b b, respectively, and so as to have a water-space aroundthem. At their inner ends the tubes E E connect with a tube, F, arrangedvertically and centrally in the main generator, and extending downwardnearly to the bottom of the generator, and there, preferably, branchinginto several branch tubes, F F F F, that radiate from the main tube Ftoward the Wall of the generator, and then, preferably, turn upward ashort distance, as shown in Fig. 2.

G G G G represent valves that seat downward onto the tubes F F F F,respectively, and serve to prevent the water or steam from entering thetubes when the air-blast (hereinafter described) is not in use.

The operation of the invention as thus far set forth is as follows: Thegenerator is filled (and, by suitable means, kept filled) with water,say, to the level of the line a; w of Fig. 2, and a fire is made in thefire chamber, and, preferably, extending from the grate upward to thetop of the chamber, and the cover B is closed and fastened. An air-blastis then,

and, preferably, by means of a suitable pumping apparatus (not shown)forced into and through the fire, and thence, together with the productsof combustion, into the generator, and there discharged into the watertherein.

H represents the tube through which the air is introduced into the firechamber. It can be made to enter the latter at any desired level, but Iprefer to divide the tube into two branches, H and B, that respectivelyenter the fire'chamber near the top and near the bottom thereof. Valvesh and h are arranged, respectively, in the branch tubes H and H, toclose either of them, as desired. Similar valves 0 and e, for a similarpurpose, are arranged, respectively, in the tubes E and E. By operatingthe valves referred to suitably the air-blast can be sent either upwardor downward through the fire, as desired. In starting, it is preferableto send the blast upward. Accordingly the valves h and e are closed, andthe valves h and 0 opened. The air then, carrying the products ofcombustion along with it, passes upward through the fire and thencethrough the tube E, tube F, and branch tubes F F F F.

I have found, however, that more of the consumable portion of the fuelis borne away from the fire-chamber into the generator in an unconsumedcondition than when the course of the air-blast is downward through thefire. Therefore, when the fire is well started, I preferably close thevalves h and e, and open the valves h and e, and direct the air-blastdownward through the tire and through the tubes E, F, and F. In eithercase the force of the blast is sufficient to open the valves Gr G G Gagainst the pressure of the water and steam, and allow the air andproducts of combustion to pass directly into the water. By this meansalmost the entire amount of heat arising from the combustion of the fuelin the fire-chamber is utilized.

The fire-chamber and tubes are contained in the water-space of thegenerator, and the entire heat-current is finally received into thewater from which the steam is formed. The steam is therefore generatedvery rapidly and economically even when the heat-currents are allowed toescape from the tubes F F F F directly upward through the water.

I have observed, however, that the air and gas currents pass up throughthe water much too rapidly to allow more than a portion of their heat tobe communicated to the water, and, in consequence, only that portion isutilized in generating the steam.

It is obvious that this difliculty cannot be overcome unless the air andgas are kept for a very much longer time in contact with the waterbefore emerging therefrom.

If the column of water in the generator were, say, one hundred feet inheight, a much larger portion of the heat might be absorbed. But agenerator of such size is impracticable. Moreover, a hydrostaticpressure proportionate to the height of the column must be overcome,increasing the difficulty in passing the currents through the water, andnecessitating a boiler-pressure greater than is frequently desirable touse.

To overcome these difficulties, and. to provide means for retaining andabsorbing all, or nearly all, the heat of the air and gas currents afterthey shall have been discharged into the generator. and without havingto use a body of water that is uncontainable in a steam-generator ofordinary size, the following mode and means are employed:

Instead of allowing the air and gas currents to pass directly upwardthrough the water, I

cause it to traverse a circuitous route through the same, and Iaccomplish this, preferably, by the following means: A screw, I, isarranged in the water-space of the generator, and in such a position asto intercept the air and gas currents as they escape upward from thetube F or tubes F F F F, and cause them to wind round and round throughthe water in their ascent.

In forming this screw the tube F may, if desired, serve as a stem forthe thread z, and the latter may extend laterally tothe side of thegenerator. I have found, however, that the air and gas currents are aptto urge the water upward along with them into the upper part of thegenerator, and that provision m net. be made for the return of suchwater to the lower part of the generator. To this end the screw, indiameter preferably, does not quite reach to the sides of the generator,and is inclosed and held in a casing, J, and leaving a space, K, betweenthe casing and the generator. It is desirable, also, to make the stemt"- of the screw independent of, and larger than,

the tube F, so as to have a space, It, between.

them.

Both of the spaces K and It are open, above and below, to thewater-space of the generator. The casing fits closely around the screw,to prevent the passage of the air or gas between. the periphery of thescrew and the casing. The

latter is,preferably, supported on brackets LL L L, and is steadiedlaterally above by the lugs j j. The casing extends downward below thelevel of the point where the air and gas are delivered into the water toprevent the air and gas from turning to the outside of the casing intothe space K. a

As it requires much more power to force a gas downward into water thanupward, the

bottom of the casing need not be more than a few'say, seven oreight-inches belowthe mouths of the tubes F F F F. The stem 2" isextended downward similarly and for a similar purpose.

The proportions and form of the screw may be varied to suit the shape ofthe generator. It is desirable to make it, in diameter, as large (makingallowance for the spaceK) as the size of the generator will permit, andthe pitch of the screw should be very finesay, three or four inches in ascrew three feet in diameter. While a screw is the most natural form ofconstruction to employ to efiect the result in question, it is obviousthat other constructions will measurably suffice. For instance,avertical series of inclined planes may be used, or even averticalseries of horizontal shelves, open, alternately, at opposite ends, willanswer to give a winding course to the gaseous with the water, andafford opportunity for their heat to be communicated to the surroundingwater, which is all around and in the screw.

An important advantage accrues from thus being able to retain theheatviz., the air and products of combustion can be heated to atemperature greatly exceeding that corresponding to even the highestpressure at which steam is ordinarily used. This high temperature isdesirable,for the ratio of incondensible air and gas finally escapingfrom the generator to the volume of steam generated will be inverselytothe temperature employed, the hotter the fire the smaller the volume ofair and gas required. Hence the proportion of the latter can be reducedto such a degree as to enable a condensing-engine to be used inconnection with the present generator.

Independent of the benefit derived from the circuitous route the watertakes in its ascent within the casing J, a further advantage is obtainedfrom dividing, by means of the easing J or other equivalent verticalpartition or partitions, the generator into d-ifl'erent compartments,and introducing the heated gaseous current or currents into the lowerend or ends of one or of a portion only of the compartments, and leavingthe other, or remaining compartment or compartments, for the return tothe lower end of the generator of the water-that is, by the heatedgaseous current or currents forced to the upper part of the generator,viz., the water is kept thoroughly and rapidlyin circulation, andthereby brought more efl'ectually in contact with the heated gaseouscurrent or currents.

M represents the usual steam-exit pipe, N

the water supply-pipe, and O a blow-ofi' cock pipe, each of which may bearranged at the most desirable part of the construction.

What I claim is 1. In a steam-generator, the screw I, substantially asand for the purpose of causing the current or currents of heated air orgas to follow a circuitous route through the water.

2. The combination of the generator A,

screw I, and casing J, substantially as described.

3. The combination of the generator A, firechamber B, tubes E and E, oreither of said tubes, tube F, screw I, and easing J, substantially asdescribed.

4.. The combination of the screw 1, casing J, and tube F, substantiallyas described.

5. The combination, in a steam-generator,

ot' the screw I, casing J, tube F, and branch tubes F F F F,substantially as described.

6. The generator A, fire-chamber B, tubes E and E, tubes H H H, andcooks h h e 0, combined and operating substantially as described.

7. The combination of the casing J and the tubes F F F F, the formerextending below the level of the mouths of the latter to prevent theescape of the gaseous current from the tubes directly into the channelsK and is, substantially as described.

8. In an aero steam-generator, the combination of a heat-retainingscrew, by which the heated gaseous or vaporous currents are caused totraverse a circuitous route in their passage upward through the water,and an independent channel or channels through which the water that isurged by said currents to the upper part of the generator can return tothe lower part of the generator.

THOS. L. JONES.

Witnesses:

PAUL BAKEWELL, CHAS. D. MOODY.

